There are two basic machines or systems for forming bags. Fill and form machines are exemplified by U.S. Pat. Nos. 2,260,064; 3,456,866; 4,290,467 and 4,726,171. Bag making machines are exemplified by U.S. Pat. Nos. 3,762,628; 3,998,135; 4,648,860 and earlier issued patents to myself.
The art has distinguished between these two systems because the fill and form machines are for packaging bulky articles for subsequent resale of the packaged product
Bag making machines make wickets of bags which when produced may comprise 50 to 200 bags which lay flat. The wickets of bags are subsequently sold for further use, deli bags, etc. Bag making machines are designed to convert flat bag stock into a wicket or bundle of flat bags by drawing the stock in a two-dimensional or planar configuration through a plurality of printing, sealing, cutting, folding and drawing stations. The sealing bars, cutting knives and drawrollers extend across the stock or partially formed bag and define a narrow or linear gap between their acting surfaces; i.e. perimeter of the drawrollers, edge of the knife and between the bag stock upon which the surfaces will act.
Others in the prior art have modified bag forming machines to form pockets or pouches in the bags and have also inserted flat pieces, cards and the like in the pockets formed in the bags. This was possible because the cards or pieces were planar and existing bag making machines could be used without any major modifications or adjustments to carry the flat pieces through the existing equipment.
The present invention is directed to a bag making machine and a method for forming bags wherein three-dimensional articles may be fed to the bag stock while the stock is being formed into a bag. The bag is subsequently formed with the three-dimensional article encapsulated on at least one side thereof. The fill and form machines do not do this and the bag forming machines of the art do not have this capability.
Broadly the invention, in one aspect, comprises a bag making machine which forms a fold on the outer surface of a bag, places a three-dimensional article within the fold in a predetermined orientation and secures the article within the fold while the bag being formed continues to travel through subsequent processing steps to form the bag. Securing the article within the fold prevents disorientation of the article as the bag is subsequently formed.
The invention, in another aspect, embodies a feeding station which inserts the articles into the fold formed on the bag.
The invention, in still another aspect, embodies a drawroller with a tensioning member which allows the article to pass through the drawrollers and which controls the force of the drawrollers acting on the bag stock on either side of the article.
The method of the invention includes feeding a sheet of bag stock having a side terminating in an edge to a sealing station. A strip of film material having at least one edge is also fed through the sealing station. The one edge of the strip is sealed to the edge of the bag stock, the strip extends over the bag stock, terminates in a free edge and defines with the bag stock a fold. A three-dimensional article is inserted into the fold. The article is secured within the fold and the free edge of the fold is sealed to the bag stock to encapsulate the material therein. Subsequently the bag with the encapsulated article is formed.